The present invention relates to a picture tube for casting an image, and more particularly, to a flat picture tube which is plane-shaped.
Generally, a picture tube casts an image by radiating a luminescent material utilizing emitted heat electrons.
FIG. 1 is a schematic diagram of a conventional color picture tube.
As shown in FIG. 1, the conventional color picture tube is constituted by an electron gun 1, deflection yokes 3 and 4, a shadow mask 6, a fluorescent plane 5 and a high-voltage power supply 7.
The electron gun 1 having three primary color red, green and blue electron guns emits red, green and blue electron beams 8.
The deflection yokes 3 and 4 converge the red, green and blue electron beams 8 emitted from the electron gun 1 into one spot of the shadow mask 6.
The shadow mask 6 having a plurality of holes formed inside the fluorescent plane 5 makes the electron beams 8 emitted from the electron gun 1 pass through one hole to emit to the fluorescent plane 5.
The fluorescent plane 5 is radiated by the electron beams 8 passed through the shadow mask 6 such that red, green and blue luminescent materials are uniformly distributed on a curved glass plane 2.
The high-voltage power supply 7 absorbs electrons used for radiating in the fluorescent plane 5 and supplies a high-voltage power to the electron gun 1.
When the high-voltage power is supplied from the high-voltage power supply 7, the red, green and blue electron gun 1 heats an internally disposed heater (not shown) to emit heat electrons and the emitted heat electrons are controlled by a plurality of grids (not shown) to then be emitted as electron beams 8.
The red, green and blue electron beams 8 emitted from the red, green and blue electron gun 1 are converged into a hole of the shadow mask 6 by means of the deflection yokes 3 and 4 to pass therethrough.
The red, green and blue electron beams 8 passing through the hole of the shadow mask 6 impinge on the red, green and blue fluorescent material of the fluorescent plane 5 to then be radiated.
However, since the conventional color picture tube should necessarily require the electron gun 1 and deflection yokes 3 and 4, the volume thereof becomes larger. Also, since high-voltage power should be supplied for emitting electron beams 8, the electricity consumption becomes higher.